Willems was the rear guard of a Brotherhood of Steel squad that took part in a mission with the Guardian Brotherhood to find out if there truly is a tunnel entrance into The Glow.

He took a sniper bullet to the shoulder early in the assault and was able to administer a stimpak himself, but was only able to fire one handed and was already preparing a tall tale of heroics, one of many that originated from the squad and which had earned them the name "Brothers Grimm" with their Guardian compatriots.

Willems was one of the first on the scene when Jenkins was attacked by the mutant mantis shrimp, and provided cover fire as Miller went in to get him. According to Willems there were at least three more mantis shrimps further down the shatter-rock beach.[1]